In order to enhance the covering effect for one sitting on a vehicle seat to prevent the centrifugal force generated during a turn of a vehicle from causing discomfort on a human body receiving the centrifugal force, a side protection portion is provided at each of two sides of a back support portion of the seat. At two sides of a waist of the human body, the two side protection portions produce a covering effect on the human body, so as to alleviate the influence of the centrifugal force on the human body in the vehicle, thus enhancing the comfort of sitting on the seat.
For example, the German Patent No. 4106863 discloses a motor vehicle seat. The motor vehicle seat is provided with a spring core at a rear of a backrest, and two sides of the spring core extend towards two sides of the backrest, respectively. An air cushion is provided at each of two sides of the backrest. When the air cushions are inflated, the two sides of the spring core are pushed to curve towards an inner side of the motor vehicle seat to push side regions to curve towards the inner side of the motor vehicle seat, achieving an effect of covering a human body.
For another example, the German Patent Publication No. 102007009891 discloses an adjusting device for a side protection of a seat. The adjusting device includes an adjusting element, a supporting unit, and a pneumatically actuating positioning unit. The adjusting element is for coupling a side protection of a seat, and includes two parts arranged angled to each other. The supporting unit includes a supporting plate that mechanically supports the adjusting element. The positioning unit (e.g., a balloon) is for positioning the adjusting element relative to the supporting unit, and is coupled to the adjusting element. When the positioning unit is actuated, the adjusting unit is re-positioned to adjust the side protection.
Further, the China Patent No. 201761399 discloses a pneumatic side clamping device including a pressing rod disposed at one side of a pressing plate. The pressing rod is disposed by means of a blocking plate on a backrest. An air cushion is provided between the pressing plate and the pressing rod so as to drive the pressing rod to rotate towards an inner side of the backrest through an operation of the air cushion.
However, although being capable of adjusting the angle of the side protections, the foregoing adjusting devices for the side protections are complicated in structure, causing assembly difficulties.